Self-energizing burner control systems of an electromechanical nature have been available for a number of years. The self-energizing systems typically use a thermoelectric generator that is made up of a group of thermocouples connected in series. These types of units have been marketed in the past, and Honeywell Inc. markets such a unit under the tradename Powerpile. The thermoelectric generator means or Powerpile is exposed to a pilot flame at a burner and generates a very low potential direct current. This very low power direct current voltage is applied to a special type of fuel valve, and is controlled by a mechanical thermostat so that the valve can be opened and closed in response to the thermostat. These types of systems have limited applications because of the frailties of the thermostat which must switch exceedingly low levels of direct current potential and current.
The cross-referenced application discloses a self-energizing burner control system in which the thermoelectric generator means or Powerpile is exposed to a pilot burner and generates a very low level of direct current potential. This very low level of direct current potential is used to drive an oscillator means. The oscillator means provides an alternating current output which is stepped up by a transformer. The output of the transformer, being higher in voltage than would ordinarily be available from a Powerpile, can be used with a rectifier and capacitor type of system to provide a direct current voltage of approximately five volts. This potential is then used to energize a very low power, solid state temperature control means. The solid state temperature control means includes a monolithic CMOS controller that is capable of being energized from approximately five volts direct current, and utilizes a very low amount of energy for its operation. The controller in turn operates a solid state switch that is in series with the valve of a type used with thermoelectric generator means.
The systems disclosed above are somewhat inconvenient to use in that manual operation of the valve means is required, while the potential from the Powerpile is initiated. A typical lighting instruction for a burner using this type of equipment would be that the manual operator should be held in an open position for at least three minutes after lighting the associated pilot to insure that the Powerpile output was adequate.